Having reliable encryption is paramount when storing valuable data on the cloud. Without a strong sense of security, there’s good reason to believe that information is vulnerable to be hacked or swiped, which could be devastating to some companies and institutions.

How much security is needed on the cloud can depend on a case-by-case basis, as every user’s information is unique. Choosing the right level of encryption is one of the most important decisions one can make when choosing a cloud storage platform, as too little can leave you vulnerable, and too much can be a poor use of money.

First, let’s define what encryption does. In a basic sense, it changes readable text — often referred to as “plaintext” — into an unreadable format that remains protected. There are a seemingly endless array of companies offering their own special kind of encryption services, and attempting to decide which is best for you can be overwhelming.

To help you in your search for the correct amount of security, here are three of the most common types of encryption — hashing, symmetric and asymmetric — and explanations on how they work.

Hashing Encryption

Hashing encryption creates a special, fixed-length signature for a message, password or set of data. Algorithms — or “hash functions” — are used to protect information, and the slightest change in info results in a completely new hash — making it incredibly difficult for hackers to invade.

The biggest difference between hashing and other types of encryption is that once data is secured, the process cannot be changed or read in any way, shape or form. “This means that even if a potential attacker were able to obtain a hash, he or she would not be able to use a decryption method to discover the contents of the original message. Some common hashing algorithms are Message Digest 5 (MD5) and Secure Hashing Algorithm (SHA).”

Symmetric Methods

Also referred to private-key cryptography, symmetric encryption is one of the oldest and more reliable forms of online security. The private key, which can be a word, number or a random combination of letters, is applied to a password to change the message in a specific way — the means of doing this depends entirely on the particular service. It could be as easy as shifting the letters in a password a certain number of places in the alphabet. For example, if your password was ABC and the algorithm pushed those letters five spaces forward, it would become EFG. Even with a password as obnoxiously simple as ABC, this encryption method makes it nearly impossible for hackers to infiltrate.

People can use this encryption method as either a “stream” cipher or a “block” cipher, depending on the amount of data being encrypted or decrypted at a time. A stream cipher encrypts data one character at a time as it is sent or received, while a block cipher processes fixed chunks of data. Common symmetric encryption algorithms include Data EncryptionStandard (DES), Advanced Encryption Standard (AES), and International Data Encryption Algorithm (IDEA).

Asymmetric Methods

Asymmetric encryption, or “public-key cryptography,” pairs two keys together to encrypt and decryption messages to ensure it is kept secure during a transfer. This method is often considered a better option than Symmetric encryption for larger businesses. According to Microsoft, using this method means “you do not have to worry about passing public keys over the Internet (the keys are supposed to be public). A problem with asymmetric encryption, however, is that it is slower than symmetric encryption. It requires far more processing power to both encrypt and decrypt the content of the message.”